Rats! Sorry Sjhotz, I hate when parts come in damaged, hope you can get a new one!

That happened to me on a used VW gas can, the dents ended up being cracks
and I learned more than I'd care to know about fixing gas cans!

Even compressed air wouldn't' pop out end/corner dents like that, maybe air and some hammer work but (and I almost bought one for fixing the gas can) one of those spot welder dent puller kits would fix it.

But again, lot's of "fixing" for a new part, probably ain't worth it if you can get a replacement, but if you get to keep it, maybe worth fixing for a spare?

I think that's worth using a stud welder/slide hammer and some massaging. If you don't feel comfortable doing it yourself look around for a more"home grown" neighborhood body shop or look for local PDR (paintless dent removal) shop as those guys can do a combination pull and massage on it....